Cardenolido-3-{8 4{40 -amino-2{40 , 3{40 , 4{40 -tridesoxy-glycosides{9 {0 and process for their manufacture

ABSTRACT

Cardenolido-3-(4&#39;&#39;-amino-2&#39;&#39;, 3&#39;&#39;, 4&#39;&#39;-tridesoxy-glycosides) of the general formula   WHEREIN R1 stands for a steroid radical of the 3hydroxycardenolide series, R2 stands for hydrogen, lower alkyl, alkenyl, cycloalkyl, phenyl, benzyl, phenylethyl, lower aliphatic acyl, or one of the acid radicals of benzoic acid, cinnamic acid or cyclohexane-carboxylic acid, and R3 stands for methyl, the CH2OR2-group or hydrogen, and a process for their preparation are described. The compounds have valuable pharmaceutical properties.

United States Patent [191 Stache et al.

[ 1 Oct. 21, 1975 CARDENOLIDO-IH4-AMINO-2,3', 4'-TRIDESOXY-GLYCOSIDES]AND PROCESS FOR THEIR MANUFACTURE [75] Inventors: Ulrich Stache,Hofheim;

Werner Fritsch, Neuenhain; Werner Haede, Hofheim;

Ernst Lindner, Frankfurt am Main, all of Germany [73] Assignee: HoechstAktiengesellschai't,

Frankfurt am Main, Germany [22] Filed: Nov. 1, 1973 [2]] Appl. No.:411,747

[30] Foreign Application Priority Data OTHER PUBLICATIONS Ginsberg, D.,Concerning Amines, p. 53, 1964, Pergman Press, New York. Smith, P. A.S., OpemChain Nitrogen Cpds., Vol. 1, p.

65, W. A. Benjamin lnc., New York. Fieser & Fiester, Steriods, p. 254,1959, Reinhold Publ. Co., New York.

Primary ExaminerJohnnie R. Brown Assistant Exarriiner-Cary B. OwensAttorney, Agent, or FirmCurtis, Morris & Safford [57] ABSTRACTCardenolido-3-[4' amino-2, 3', glycosides] of the general formula4'-tridesoxywherein R stands for a steroid radical of the 3-hydroxycardenolide series, R stands for hydrogen, lower alkyl, alkenyl,cycloalkyl, phenyl, benzyl, phenylethyl, lower aliphatic acyl, or one ofthe acid radicals of benzoic acid, cinnamic acid orcyclohexanecarboxylic acid, and R stands for methyl, the CH OR -gr0up orhydrogen, and a process for their preparation are described. Thecompounds have valuable pharmaceutical properties.

11 Claims, N0 Drawings CARDENOLIDO-FH4'-AMINO-2', 3',4'-TRIDESOXY-GLYCOSIDES] AND PROCESS FOR THEIR MANUFACTURE The presentinvention relates to cardenolido-3-[4- amino-2', 3,4'-tridesoxy-glycosides1 and to a process for their manufacture.

According to Bull. Soc. Chim. France 1971, page 864,3-methoxy-4'-amino-glyco-cardenolides are known to have a possiblecytostatic activity. However, cardenolido-4'-amino glycosides carryingunsubstituted methylene in the 2-and 3-positions. especially thosehaving cardiac activity, have as yet not been disclosed.

This invention now provides cardenolido3-[4- amino-2, 3,4,tridesoxyglycosides] of the formula I in which R, stands for a steroidradical of the 3- hydroxycardenolide series, R stands for hydrogen oralkyl having 1 to 4 carbon atoms, alkenyl having 2 to 4 carbon atoms,cycloalkyl having 3 to 7 carbon atoms, phenyl, benzyl, phenylethyl,aliphatic acyl having 1 to 4 carbon atoms, or one of the radicals ofbenzoic acid, cinnamic acid or cyclohexanecarboxylic acid, and R standsfor methyl, the -CH OR group or hydrogen.

The present invention moreover relates to a process for themanufactureof cardenolido3-[4-amino-2, 3, 4-tridesoxy glycosides] of theabove-specified formula I, which comprises reacting a cardenolido-3-l2,3'- didesoxy-glycoside] of the formula II in which R, and R are definedas above, with an alkylor aryl-sulfonic acid halide of the formula IIIR, so Hal III in which R, stands for alkyl having 1 to 4 carbon atoms,cycloalkyl having 3 to 9 carbon atoms, phenyl, phenyl or benzyl eachsubstituted by one, two or thre methyl groups, in the presence of atertiary organic base and, preferably, in an inert solvent to yield thecorresponding sulfonic acid ester of the formula IV in which R R and R,are defined above, reacting the compound of the formula IV with analkali metal azide in an aprotic inert solvent at a temperature of from0C to the boiling point of the reaction mixture used, to yield thecorresponding azide of the formula V in which R and R are defined asabove, the substituent in 4-position being reversed according to Walden,hydrogenating the azide of the formula V in the presence ofa metalcatalyst in an inert solvent to yield the corresponding amine, and whererequired, alkylating or acylating, according to the definition of R thecompound of the formula I thus obtained, having a free amino group,and/or a compound of the formula I, in which R stands for CH OH, orwhere required, deacylating a compound of the formula I, in which R,stands for -CH O-acyl, by means of an alkaline agent As startingmaterial may, for example, by mentionedthe following cardenolido-3-[2,3-didesoxyglycosides] which may be prepared according to the processdisclosed in German Offenlegungsschrift No. 1,943,901 and whose steroidradicals R in formula I are preferred:

Digotoxigenin-, gitoxigenin-, digoxigenin-, periplogenin-,l9-carobxy-methylene-periplogenin-SB-lactone-,l9-cyano-methylene-periplogenin-, uzarigenim, K-strophanthidin-,K-strophanthidole-, ouabageninor oleandrigenin-3[2,3-didesoxy-glycosides]of the above-cited formula II.

The glycoside moiety of these compounds is based on glucose, rhamnose,arabinose, xylose or mannose, preferably on glucose and rhamnose, thislatter both in the a-L-and a-Dform. In the glycoside moiety, the radicalR in the above formula II may, for example, have the following meanings:

Hydrogen, methyl, ethyl, propyl, propenyl, cyclohexyl, phenyl, benzyl,formyl, acetyl, propionyl, butyryl, benzoyl, cinnamoyl or cyclohexoyl.

In the first reaction step II IV, methane-sulfonic i acid chloride,p-toluene-sulfonic acid chloride and brosyl chloride are preferably usedas sulfonic acid halides.

In the first reaction step, the starting cardenolide is dissolved in atertiary organic base, such as pyridine, quinoline, collidine,triethylamine or N-diethyl-aniline, where required with the addition ofan inert organic solvent, such as tetrahydrofuran, dioxan, toluene orbenzene. To this mixture, the alkylor aryl-sulfonic acid chloride,advantageously in admixture with the tertiary organic base or with thesolvent, is added dropwise. The reaction mixture is then stirred at apreferable temperature of 20 to +60C and then worked up in the usualmanner, for example by pouring it into water and suction filtering orextracting the sulfonic acid ester with a solvent which is not misciblewith water, such as chloroform or methylene chloride.

In the second reaction step IV- V, sodium azide,

potassium azide or lithium azide are preferably used as azides. Thecardenolide and the alkali metal azide are dissolved or suspended in apolar aprotic solvent, prefcrahly dimethylformamidc, dimethylsulfoxideor N.N,- N.N,N,N-hcxamethylphosphoric acid triamide, and'the reactionmixture is treated over a period of minutes to 24 hours at a temperatureof from 0 to the boiling point of the reaction mixture. The reactionproduct is worked up in the usual manner, for example by pouring it intowater and suction-filtering or extracting it in the same manner asdisclosed for the first step.

In the third reaction step V v 1, the following cata lysts are, forexample, used for the catalytic hydrogenation of the azide compound:palladium, platinum, rhodium, zinc, nickel or iridium catalysts, ormixtures of these catalysts, preferably palladium catalysts, for examplepalladium black or palladium on barium carbonate or strontium carbonate.

As solvents suitable for the catalytic hydrogenation,

there are mentioned, for example, methylene chloride,

chloroform, dichloroethane, tetrahydrofuran, dioxan, methanol, ethanol,propanol, benzene, toluene or mixtures of these solvents.

Catalytic hydrogenation is carried out according to usual methods atnormal pressure or an excess pressure of up to about 50 atmospheresgauge at a temperature of 0 to 70C, preferably to 50C, in an apparatussuitable for catalytic hydrogenation. Infrared spectroscopic checking ofsamples that have been taken from the hydrogenation vessel permitsdetermining when hydrogenation has come to an end. After thecharacteristic infrared band of the azide group at about 2090 cm hasentirely disappeared, hydrogenation is complete.

The catalyst is then separated from the reaction solution by filtration,the filtrate is concentrated and the residue is recrystallized from asuitable solvent, for example from a high-boiling ether and/or acetone.

1f the cardenolido-Z, 3, 4-tridesoxy-glycosides thus obtained containester groups in their glycoside moiety, these may be converted into freealcohol groups by the usual hydrolysis, for example with ammonia inmethanol or potassium carbonate in alcohol/water.

The free amino group in 4'-p0sition may be acylated, where required, forexample by a reaction with carboxylic acid anhydrides or halidesaccording to the SchottenBaumann method. It may also be alkylated, forexample by a reaction with alkyl halides in the presence of silvercompounds or alkali metal or alkaline earth metal salts.

It is a surprising fact that catalytic hydrogenation of the 4'-azidegroup to the 4-amino group takes place so preferably prior tohydrogenation of the 20(22)-double bond that a selective hydrogenationprovides the products of the invention in good yields. For it is knownthat the double bond of the 17B-butenolide ring is hydrogenated undersimilar conditions (cf. Fieser Steroide, Weinheim/Bergstrasse 1961,pages 811 et seq.).

The cardeno1ido-3-[4-amino-2', 3', 4-tridesoxyglycosides] according tothe invention have valuable pharmaceutical properties. For example, theyshow cardiotonic efficacy, especially a high positively inotropicactivity which has been tested on an isolated atrium of a guinea pigsheart or by potassium excretion on an isolated guinea pigs heart. Thecompounds according to the invention are therefore suitable for thetreatment of cardiac insufficiency. Moreover, they exhibit acytostaticeffect and may therefore be used for treating tumors.

The novel compounds are predominantly used as orally'administrabletherapeutics in the form of tablets, capsules, drages, to which theusual pharmaceutical carriers, for example starch. lactose, tragacanth,magnesium stearate and talcum. may be admixed. For intravenousinjections, water or a physiological sodium chloride solution is used.

The individual dosage to be administered to human beings the range offrom about 0.5 mg to 5 mg per dosage unit form.

The following Examples serve to illustrate the invention.

EXAMPLE 1 Digitoxigenin-3-L-[2, 3-didesoxy-rhamnopyranosido-4-ptoluenesulfonate] A solution of 1.7 g of p-toluene-sulfonic acidchloride in 19.7 ml of pyridine was added dropwise while stirring at 0Cto a solution of 2.44 g of digitoxigenin-3-L- [2,3'-didesoxy-rhamnoside] (prepared according to GermanOffenlegungsschrift No. 1,943,901). Stirring was continued for 20 hoursat room temperature and the reaction mixture was poured into 200 ml ofwater. After having been allowed to stand for 1 to 2 days, thesupernatant material was decanted off from the precipitate, theprecipitate was taken up in methylene chloride, washed with water, driedand concentrated under reduced pressure. The foamy substance obtainedwas crystallized from diisopropyl ether.

Yield: 2.6 grams of digitoxigenin-3-L-[2', 3-didesoxy-rhamno-pyranosido-4-p-toluene-sulfonate],

Melting point: l20-121C.

Characteristic infrared bands (in KBr): 3500, 1780, 1755, 1740, 1620,1595, 1490, 1360, 1190, 1175, 1030, 995, 960, 835, 810 cm.

In the same manner as K-strophanthidin-3-L-[2,rhamnopyranosido-4'-p-toluene-sulfonate1 was obtained fromK-strophanthidin-3-L-[2, 3'-didesoxyrhamnoside],(19-carboxymethylene-periplogenin5B-lactone-3-L-[2,3'-didesoxy-rhamnopyranosido-p-toluene-sulfonate] wasobtained from 19- carboxymethylene-periplogenin-SB-lactone)-3-1 ,-[2', 3-didesoxy-rhamnoside uzarigenin-3-L-[ 2 3didesoxy-rhamnopyranosido-p-toluene-sulfonate1 was obtained fromuzarigenin-3-L-[2, 3-didesoxyrhamnoside].

disclosed above,

3-didesoxy- EXAMPLE 2 Digitoxigenin-3-L-[2', 34-tridesoxy-rhamnopyranosido-4a-azide] A solution of 1.28 g ofdigitoxigenin-3-L-[2, 3'-didesoxy-rhamnopyranosido-4-p-toluene-su1fonate] in 32.2 ml ofN,N,N,N,N,N-hexamethyLphosphoric acid triamide was combined with 3.25 gof sodium azide,

and the mixture was stirred for 3 hours at C under an atmosphere ofnitrogen. The reaction mixture was then poured into 300 ml of watercontaining sodium chloride, the precipitate was suction-filtered anddried under reduced pressure over phosphorus pentoxide.

1.3 g of digitoxigenin-3-L-[2, 3, 4'-tridesoxyrhamnopyranosido-4a-azide]were obtained, m.p. 102106C.

Characteristic infrared bands (in KBr): 3480, 2095 (very pronounced),1780, 1740,1620, 1020, 990 cm.

were used to'prepare: K-strophanthidine-B-L-l2', 3,

4-tridesoxywhamnopyran'osido-4a-azidcl, I (l9-carboxymethylene-periplogenimSB-lactone)-3-L [2',3'-didesoxy-rhamnopyranosido-4 or-azide1 and uzarigenin-3-L -[2-,3'-didesoxy-rhamnopyranosido-4r a-azide].

EXAMPLE, 3,

Dixitoxigenin-3-L-[2', 3, 4'-tridesoxy-4a-amino-rhamnoside1 1.75 g ofdigitoxigenin-3-L-[2', 3-didsoxy'- rhamnopyranosido-4'oz-azide] weredissolved in 140 ml' of ethanol and the solution was catalyticallyhydroge.

natedvwith 710 mg of 10 Pd/CaCO- (prehydrogenated in50 .mlofethanol).The hydrogenation roce.- dure was controlled by infrared spectroscopy.After the azide band. at.21 00 had disappeared, hydrogenation wasdiscontinued The catalyst was separated from the reaction solution byfiltration, the solution was'concentrated under reducedpressure and thefoamy substance obtained was crystallized by means of diisopropylEXAMPLE 4 Digitoxigenin-3-L-[2, 3',4'-tridesoxy-4a-acetamino-rhamnoside] 2 ml of acetic acid anhydride wereadded to a solution of 750 mg of digitoxigenin-3-L-[2', 3'. 4'-

tridesoxy-4'a amino-rhamnoside] in 2 ml of pyridine, and the mixture wasallowed to stand for 18 hours at 20C. The reaction mixture wasthenpoured into 50 ml of water containing sodium chloride, the liquid wasfiltered from the oily substance which had precipitated, this substancewas taken up in methylene chloride,

, washed with water, dried, and the solvent was distilled off. The foamysubstance obtained was crystallized from diisopropyl ether in a yield of524 mg of digitoxigenin-3-L-l2, 3',4'-tridesoxy-4a-acetaminorhamnoside]. After recrystallization fromacetone/ether, the compound melted at 278-280C.

Characteristic infrared bands (in KBr): 3440, 3320,

EXAMPLE 5 Digitoxigenin-3-D-[2, 3 -didesoxy-xylosido-4-p-toluene-sulfonate] 1n the manner disclosed in Example 1, 2.44 g ofdigitoxigenin-3-D-[2', 3-didesoxy-xyloside] were reacted withp-toluenesulfonic acid chloride and the reaction product was likewiseworked up, yielding Characteristic infrared bands (in KBr): 3480, 1780,1755, 1740, 162-0. 1590, 1490, 1360, 1190, 1170, 1025. 990, 960 cm''-.

' EXAMPLE 6 Digitoxigenin-3-D-[2', 3', 4"tridesoxy-xylosido-4a-azide]1.2g of digitoxigenin-3-D-[2, 3-didesoxy-xylosido-4'-p-toluene-sulfonate] were reacted with sodium azide and worked up asdisclosed in- Example 2. Digitoxigenine-3-D-[2, 3',4-tridesoxy-xylosido-4'rx-azide] was obtained, m.p. 9 8-l03C.

The infrared spectrum showed a pronounced band for azideat 2095-2100 cm.

EXAMPLE 7 Digitoxigenin-3-D-[2'y3', 4'-tridesoxy-4a-amino-xyloside] Asdisclosed in Example 3, 1.7 g of digitoxigenin-3- D-f2, 3',4-tridesoxy-xyloside{Va-azide]' were catalytically hydrogenated withPd/CaCOg'an'd workedup', yielding digitoxigenin-3-D-[2', 3',4'-tridesoxy-4'- amino-xyloside] having charactefristic bands for theamino group at 3260 and 3170 cm". Ultraviolet spectrum: )tmax. 217 ma, 515700.

The starting compounds were prepared in the following manner:

Digitoxigenin-3-[2', 3-didesoxy-A -D-xylosido-4'-acetate1 1.8 ml ofdiacetyl-D-xylal and 0.07 ml of phosphoroxy chloride were added to asolution of 1.1 g of digitoxigenin in 9.6 ml of absolutetetrahydrofuran. After stirring had been continued for 5 hours at 20 to25C (care should be taken not to heat the reaction mixture above 40Csince undesired by-products which are difficult to separate may form,thus reducing the yield), the reaction mixture was poured into 50 ml ofwater containing excess sodium bicarbonate, the solution wasexhaustively extracted with chloroform, the extracts were washed withwater, dried and the solvents were distilled off under reduced pressure.A residue of about 2.5 g was obtained as an oil which graduallycrystallized upon trituration with ether. The crystals were thensuction-filtered and washed with a small amount of cold ether. 0.76 g ofdigitoxigenin-3-[2', 3'- didesoxy-A -D-xylosido-4'-acetate] wasobtained, m.p. l27l39C (Kofler heating device).

Characteristic infrared bands (in KBr): 3500, 1780, 1750, 1730, 1620,1230, 1020, 740 cm.

Ultraviolet spectrum (in methanol): Amax 216-217 m p.;e=l6200.

Digitoxigenin-3-D-[2', 3 -didesoxy-4 -O-acetyl-xyloside] A solution of3.7 g of digitoxigenin-3-D-[2', 3-didesoxy-4'-O-acetyl A -xyloside] in300 ml of ethanol was added to a preliminarily.hydrogenated suspensionof 1.5 g of palladium on calcium carbonate (10%) in ml of ethanol, andthe mixture was hydrogenated under normal pressure at 22C. After 1molequilvalent of H ml) had been absorbed, hydrogenation came to astandstill. The catalyst was separated from the reaction solution byfiltration and the filtrate was concentrated under reduced pressure. Theoil obtained as a residue was crystallised from ether/nhexane. 2.7 g ofdigitoxigenin-3-D-l2', 3'-didesoxy-4- O-acetyl-rhamnoside] wereobtained.

Characteristic infrared bands (in KBr): 3500. 1775, 1735 (broad), 1620,I235. I025, 990 cm.

Digitoxigenin-3-D-[2', 3'-didesoxy-xyloside] A solution of 660 mg ofpotassium bicarbonate in 6.6 ml of water was added to a solution of 2.2g of digitoxigenin-3-D-l2, 3-didesoxy-4-O-acetyl- Xyloside] in 70 ml ofmethanol and the mixture was refluxed for minutes. After cooling, thereaction mixture was poured into 500 ml of water containing sodiumchloride, the precipitate which had separated was suction-filtered,washed and dried. After recrystallization from acetone/ether, 1.2 g ofdigitoxigenin-3-D- [2, 3'-didesoxy-xyloside] were obtained.

Characteristic infrared bands (in KBr): 3400 (broad), 1780, 1720, 1620,1090, 1015, 990 cm'.

Ultraviolet spectrum: )tmax. 217 m me l6l00.

We claim:

5. Digitoxigenin-3-L-l2, 3', 4'-tride soxy-4aacetylamino-rhamnoside] 6.Digitoxigenin-3-D-[2', 3'-didesoxy-xylosido-4'-p- I toluene-sulfonate]7. Digit0xigenin-3-D-[2, 3, 4'-tridesoxy-xylosido-r 4a-azide] I 8.Digitoxigenin-3-D-[2', 3', 4'-tridesoicy-4a-amino; xyloside] H I 9.K-Strophanthidin-3-[2', 3', 4-tridesoxy-4'aaminorhamnoside] A l0.l9-Carboxymethylene-periplogenin-Sfidactone)-3-L-[ 2', 3 4 -trides0xy-4"a-amino-rhamnosid'e] rhamnoside]

1. A CARDENOLIDO-3-(4''-AMINO-2'',3''4''-TRIDESOXYGLYCOSIDE) OF THE FORMULA
 2. Digitoxigenin-3-L-(2'', 3''-didesoxy-rhamnopyranosido-4''-p-toluene-sulfonate)
 3. Digitoxigenin-3-L-(2'', 3'', 4''-tridesoxy-rhamnopyranosido-4'' Alpha -azide)
 4. Digitoxigenin-3-L-(2'', 3'', 4''-tridesoxy-4'' Alpha -aminorhammoside)
 5. Digitoxigenin-3-L-(2'', 3'', 4''-tridesoxy-4'' Alpha -acetylamino-rhamnoside)
 6. Digitoxigenin-3-D-(2'', 3''-didesoxy-xylosido-4''-p-toluene-sulfonate)
 7. Digitoxigenin-3-D-(2'', 3'', 4''-tridesoxy-xylosido-4'' Alpha -azide)
 8. Digitoxigenin-3-D-(2'', 3'', 4''-tridesoxy-4'' Alpha -amino-xyloside)
 9. K-Strophanthidin-3-(2'', 3'', 4''-tridesoxy-4'' Alpha -aminorhamnoside)
 10. (19-Carboxymethylene-periplogenin-5 Beta -lactone)-3-L-(2'', 3'', 4''-tridesoxy-4'' Alpha -amino-rhamnoside)
 11. Uazarigenin-3-L-(2'', 3'', 4''-tridesoxy-4'' Alpha -amino-rhamnoside) 